A domestic humidifier is a common home based electrical appliance which actively brings moisture into the indoor air and raises the water saturation content in the air. Most such humidifiers include mechanisms which break down the surface tension of water and carry the aerosolized water molecules into the air. All such mechanisms require a water tank and some kind of aerosolizing device. Some humidifiers make use of an ultra-sonic transducer to create fine water droplets and carry the water droplets by means of convection and directional air flow. A shortcoming of such a kind of apparatus is that water droplets of varying sizes are created, and noise is usually generated by the ultra-sonic transducer. Sometimes larger water droplets generated by the transducer will be blown out by a fan blower and be attached on an indoor surface before being evaporated into the air. Adhesion of water droplets on an indoor surface is clearly not desirable.
In some other humidifiers, aerosolizing of water molecules is achieved by steam generated by the humidifiers. This means that a heating element is required and a water tank has to be coupled to with a water reservoir in the apparatus. Such an arrangement will at least slightly increase the indoor temperature and is more energy consuming in that electricity has to be supplied for operating the heating element. In addition, as heat is generated, more care has to be taken for safety reason.
Moreover, all such existing humidifiers also require a water tank coupled to service a water reservoir. Almost all such conventional humidifiers make use of some kind of vacuum mechanism to fill the reservoir when water is consumed during operation, and thus water level is lowered. In order to operate in such a manner, the water tank should always be kept air tight. There is then the risk of water leakage out of the system as the water tank may have unnoticed cracks in which case air-tightness cannot be maintained.
It is thus an object of the present invention to provide a humidifier in which the aforesaid shortcomings are mitigated, or at least to provide a useful alternative to the public.